探討LC53抑制人類單核球細胞表現基質金屬蛋白酵素之機制及其對視網膜退化之保護作用

The Investigation of Inhibitory Mechanisms of LC53 on Monocytic Matrix Metalloproteinase-9 Expression and its Protective Effects of Retinal Degeneration

余敏(Min Yu)

指導教授 ： 蕭哲志

臺北醫學大學/醫學院/醫學科學研究所/碩士(2017年)

摘要

青光眼(glaucoma)屬於一種慢性退化性視神經病變，主要會造成視網膜病變，導致視神經受損進而造成視力喪失。目前青光眼治療多著重在控制眼壓，且藥物副作用易造成眼睛併發症，因此其相關輔助及新治療與緩解藥物的開發相當具潛力及重要。文獻指出在青光眼的初期階段，可觀察到單核球異常活化並大量表現在視網膜中。基質金屬蛋白酵素(matrix metalloproteinases, MMPs)及單核細胞趨化蛋白 (monocyte chemotactic protein-1, MCP-1)等發炎介質均會參與視網膜病變與病程。真菌萃取物LC53，分離自臺灣株炭角菌科(Theissenia cinerea)，本研究在探討LC53抑制單核球活化機制及相關發炎反應與減緩視網膜損傷作用。根據實驗結果發現， LC53在青光眼動物模式中，減少由高眼壓損傷所造成的b波與Scotopic threshold response (STR)的嚴重破壞。除此之外，LC53也降低青光眼模式下視網膜MMP-9的活性表現。在發炎細胞實驗中，LC53可以依濃度關係抑制單核球中MCP-1所誘導的MMP-9活性，但不影響MMP-9抑制劑TIMP-1的活性表現。 同樣地，LC53也能抑制單核球中MCP-1誘導的MMP-9蛋白質表現。在訊息路徑中，LC53以濃度梯度效應減少由MCP-1所誘導p65、IKK與ERK MAPK的磷酸化，但對p38 MAPK與AKT的磷酸化沒有意義上的影響。由上述結果可知，LC53可以藉由降低單核球活化與發炎反應以減緩青光眼所引發的視網膜損傷，並且可以透過NF-B訊息與ERK MAPK的路徑達到抑制效果。因此天然物成分LC53可以作為緩解及治療青光眼相關視網膜損傷之參考。

關鍵字

青光眼 ； 基質金屬蛋白酵素 ； 單核細胞趨化蛋白

並列摘要

Glaucoma is a degenerative optic neuropathy, which could cause damage to optic nerve and lead to vision loss. Much evidence indicated that monocytes recruitment and activation increased in retina at the early stage of glaucoma. Increasing production of inflammatory mediators such as MCP-1 and MMPs would exacerbate the progression of retinopathies. The fungal product, LC53, was isolated from Theissenia cinerea in Taiwan. We aim to explore inhibitory mechanisms of LC53 on monocyte activation and protective effects of glaucoma-related retinopathies. In glaucoma rat model, we found that pretreatment with LC53 functional effectively improved the impairment of scopic threshold reponses (STR) and b-wave in electroretinogram (ERG) . In addition, LC53 successfully reduced the gelatinolytic activity of optic MMP-9 and the expression of COX-2 in the model of glaucoma. In vitro studies indicated that LC53 could concentration-dependently inhibit MCP-1-induced MMP-9-mediated gelatinolysis in activated monocytic THP-1, but the acitivity of MMP inhibitor (TIMP) -1 was not affected. Consistently, LC53 also attenuated MMP-9 expression in MCP-1-induced THP-1 activation by Western blotting. Among the signaling pathways, this natural compound decreased the phosphorylation of p65, IKK and ERK MAPK in a concentration-dependent manner. However, LC53 had weak effects on the phosphorylation of p38 MAPK, and AKT. Taken together, LC53 ameliorated glaucoma-induced ocular injuries through its reduction of monocyte activation and ocular inflammation by the inhibition of NFB and ERK MAPK signalings. It was suggested that LC53 might have therapeutic potential for the treatment of glaucoma-related retinopathies.

並列關鍵字

glaucoma ； MMP ； MCP-1

參考文獻

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